It has long been recognized as necessary for the control of some insects and some herbs or weeds in large scale farming operations that it is necessary to use a spray technique to assure reasonable coverage. In the past the spray technique has been handled by mobile spray units either transporting a bulk tank of spray along the ground and spraying the necessary area or alternatively transporting the premixed sprays in airplanes and covering the area from the air. The presently used procedure has presented problems in that the spray was required to be premixed and therefore if the spray was not used because of an incorrect quantity or adverse weather conditions it had to be dumped or disposed of in some other way. The Environmental Protection Act has prohibited the dumping of any toxic material under the threat of a very large fine. It has therefore become a problem of how to handle excess chemical material at the end of the spray or premixed chemicals impossible to be utilized because of weather or other adversity.
Another problem with the previous method of spray control is in the fact that the individuals doing the spraying have had to premix the spray with the diluting liquid under conditions which are not designed for safety. The concentrated spray material is very toxic and dangerous and accidental contact with the individual would result in death under some circumstances. It is far preferable that the toxic material be handled only by trained personnel in the manufacturing facility of the material where proper safety procedures may be instituted. Thus untrained and perhaps unwary individuals such as the people who actually do the spraying need not come into any contact whatsoever with the concentrated material.
With the bans upon any material that has a persistent life the available chemicals for use have a short life. These short lived chemicals will deteriorate in a premixed tank in a very short amount of time, therefore eliminating the possibility of storing these chemicals.
One of the solutions to the problems noted above is in the use of a concentrated chemical which is mixed only on an as-needed basis and preferably, ahead of the spray nozzle itself, so that there would be little or no waste whatsoever. Mixing ahead of the nozzle has the advantage in that the spray operator does not have to contact any of the concentrated chemical but need only direct the spray, which is of a dilute substance.
Prior patents dealing with the mixture of two or more substances and pertinent to the invention known to the inventor are U.S. Pat. No. 2,573,949 granted Nov. 6, 1951, to Blizzard; U.S. Pat. No. 3,592,386 granted July 13, 1971, to Tschudy; and U.S. Pat. No. 3,640,461 granted Sept. 26, 1969, to Koll.
With the foregoing problems and prior art in mind, it is an object of the present invention to provide a mechanism whereby a concentrated chemical and a diluting material may be admixed ahead of the nozzle immediately prior to the spraying of the substance.
Another object of the present invention is to provide a spray control mechanism wherein the operator upon opening or closing the nozzle controls the supply pumps. The liquid flow is thereby controlled by the operator by controlling the nozzle.
Still another object of the present invention is a pumping mechanism for accurately mixing and pumping through a spray nozzle a concentrated material and a diluting material. The two materials are supplied by separate pumps and the interconnection between the pumps is of such a nature that the relative pumping speed or liquid flow is a constant, assuring a consistent end product having the prescribed proportions.